Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 70
Filtrar
1.
Sci Rep ; 12(1): 12310, 2022 07 19.
Artigo em Inglês | MEDLINE | ID: mdl-35853977

RESUMO

Infants developing necrotizing enterocolitis (NEC) have a different metabolomic profile compared to controls. The potential of specific metabolomics, i.e. amino acids and amino alcohols (AAA), as early diagnostic biomarkers for NEC is largely unexplored. In this multicenter prospective case-control study, longitudinally collected fecal samples from preterm infants (born <30 weeks of gestation) from 1-3 days before diagnosis of severe NEC (Bell's stage IIIA/IIIB), were analyzed by targeted high-performance liquid chromatography (HPLC). Control samples were collected from gestational and postnatal age-matched infants. Thirty-one NEC cases (15 NEC IIIA;16 NEC IIIB) with 1:1 matched controls were included. Preclinical samples of infants with NEC were characterized by five increased essential amino acids-isoleucine, leucine, methionine, phenylalanine and valine. Lysine and ethanolamine ratios were lower prior to NEC, compared to control samples. A multivariate model was rendered based on isoleucine, lysine, ethanolamine, tryptophan and ornithine, modestly discriminating cases from controls (AUC 0.67; p < 0.001). Targeted HPLC pointed to several specific AAA alterations in samples collected 1-3 days before NEC onset, compared to controls. Whether this reflects metabolic alterations and has a role in early biomarker development for NEC, has yet to be elucidated.


Assuntos
Enterocolite Necrosante , Doenças do Recém-Nascido , Aminas , Estudos de Casos e Controles , Enterocolite Necrosante/diagnóstico , Enterocolite Necrosante/metabolismo , Etanolaminas , Humanos , Lactente , Recém-Nascido , Recém-Nascido Prematuro/metabolismo , Isoleucina , Lisina
2.
J Med Eng Technol ; 46(5): 345-353, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35311595

RESUMO

Disposable face masks are among the personal protective equipment (PPE) that highly contribute to protecting people in the context of the current COVID-19 pandemic. Health authorities recommend wearing a mask as a barrier measure to limit the spread of viral respiratory diseases. During the first waves of the pandemic, besides professional high-quality PPE, decontaminated disposable mask reuse and homemade cloth masks were allowed due to scarcities. This work introduces a simple method based on-time history of the differential pressure, and an easy to use the setup for the testing of different kinds of respiratory protective masks for the purposes of quality control and evaluation of air permeability performance. The standard mask testing method and the new proposed approach were then used to evaluate the effect of machine washing on the widely used type of disposable masks; namely the surgical (medical) face masks. The objective is to determine the number of acceptable washing cycles that this kind of mask can withstand before losing its performance in terms of breathability and airflow resistance. Other quality characteristics such as material (fibres) degradation and hydrophobicity are investigated. Degradation mechanisms due to washing cycles for the different mask constituent layers were studied by scanning electron microscopy (SEM) imaging. This work is an attempt to contribute to the determination of the reusability threshold of general-purpose disposable surgical type face masks thereby contributing to the reduction of environmental concerns. Results in terms of the studied above parameters suggest limiting the reuse of standard type surgical masks to only one machine washing cycle.


Assuntos
COVID-19 , Máscaras , COVID-19/prevenção & controle , Humanos , Pandemias/prevenção & controle , Equipamento de Proteção Individual , SARS-CoV-2
4.
Br J Biomed Sci ; 78(1): 47-52, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32552415

RESUMO

Typical presentations of Coronavirus Disease 2019 (Covid-19) including respiratory symptoms (cough, respiratory distress and hypoxia), fever and dyspnoea are considered main symptoms in adults, but atypical presentation in children could be a diagnostic challenge. We report three children whose initial presentation was gastrointestinal, and in whom Covid-19 infection was found, concluding that cases of acute appendicitis, mesenteric adenitis and flank tenderness may mask an infection with this virus, and should therefore be investigated.


Assuntos
Dor Abdominal , Apendicite , COVID-19 , Dor Abdominal/diagnóstico , Dor Abdominal/virologia , Apendicite/diagnóstico , Apendicite/virologia , COVID-19/complicações , COVID-19/diagnóstico , COVID-19/patologia , Criança , Pré-Escolar , Tosse , Feminino , Cefaleia , Humanos , Pulmão/diagnóstico por imagem , Pulmão/patologia , Masculino , SARS-CoV-2 , Vômito
12.
J Nanosci Nanotechnol ; 18(7): 4565-4579, 2018 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-29442633

RESUMO

Heteroatom doping into carbon structures is an effective approach to enhance the electrochemical performance of carbon materials. In the work presented here, the electrocatalysts including: nitrogen and co-doped nitrogen and sulfur on porous graphene (PG) were synthesized by different precursors. The physico-chemical properties of the prepared samples were determined using X-ray Diffraction (XRD), Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), N2 sorption-desorption, Transmission electron microscopy (TEM), Field Emission Scanning Electron Microscopy (FESEM) and X-ray photoelectron spectroscopy (XPS). The prepared samples were further applied for oxygen reduction reaction (ORR) and the effects of pyrolysis temperature, precursor type and dose, on the prepared samples structure and their electrochemical performances were investigated. The results revealed that synergistic effect of nitrogen and sulfur co-doped on the graphene structure leads to improvement in catalytic activity and current. Furthermore, S and N co-doped graphene prepared using sulfur trioxide pyridine complex exhibited excellent methanol tolerance and long-term stability.

13.
Sci Rep ; 7: 40606, 2017 01 16.
Artigo em Inglês | MEDLINE | ID: mdl-28091572

RESUMO

Noradrenaline is believed to support cognitive flexibility through the alpha 2A noradrenergic receptor (a2A-NAR) acting in prefrontal cortex. Enhanced flexibility has been inferred from improved working memory with the a2A-NA agonist Guanfacine. But it has been unclear whether Guanfacine improves specific attention and learning mechanisms beyond working memory, and whether the drug effects can be formalized computationally to allow single subject predictions. We tested and confirmed these suggestions in a case study with a healthy nonhuman primate performing a feature-based reversal learning task evaluating performance using Bayesian and Reinforcement learning models. In an initial dose-testing phase we found a Guanfacine dose that increased performance accuracy, decreased distractibility and improved learning. In a second experimental phase using only that dose we examined the faster feature-based reversal learning with Guanfacine with single-subject computational modeling. Parameter estimation suggested that improved learning is not accounted for by varying a single reinforcement learning mechanism, but by changing the set of parameter values to higher learning rates and stronger suppression of non-chosen over chosen feature information. These findings provide an important starting point for developing nonhuman primate models to discern the synaptic mechanisms of attention and learning functions within the context of a computational neuropsychiatry framework.


Assuntos
Agonistas de Receptores Adrenérgicos alfa 2/farmacologia , Guanfacina/farmacologia , Aprendizagem/efeitos dos fármacos , Psiquiatria , Reforço Psicológico , Agonistas de Receptores Adrenérgicos alfa 2/administração & dosagem , Animais , Cognição/efeitos dos fármacos , Macaca mulatta , Modelos Psicológicos , Análise e Desempenho de Tarefas
14.
Anat Histol Embryol ; 46(2): 204-212, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27990670

RESUMO

Magnetic resonance imaging (MRI) was used to scan the head of a common dolphin (Delphinus delphis) in order to visualize the different adipose tissues involved in echolocation functioning and to precisely delineate their anatomical topology. MRI scans were performed on the head taken from a freshly stranded carcass and repeated after a 2-week freezing time followed by thawing. The main fatty organs of the head, that is the melon, the mandibula bulba, the bursae cantantes, and their different connections with surrounding tissues were identified and labelled. The nasal sacs, other organs of echolocation, were also identified and labelled thanks to different MRI acquisitions. The shape, the location, the type of MRI signal of each organ and of their different connections were successfully analysed on all images, and then, the images of the head fresh or after thawing were compared. No impacts of the freezing/thawing cycle on the fatty tissues of the head were identified. Different parts were distinguished in the melon on the basis of the MRI signal emitted, corresponding most likely to the internal and external melon already identified by other analytical approaches, and linked to differences in lipid composition. MRI is shown here to be a useful tool to study the functional anatomy of the organs responsible for echolocation in odontocetes, with a particularly high level of precision.


Assuntos
Tecido Adiposo/anatomia & histologia , Golfinhos Comuns/anatomia & histologia , Cabeça/diagnóstico por imagem , Imageamento por Ressonância Magnética/veterinária , Tomografia Computadorizada por Raios X/veterinária , Tecido Adiposo/diagnóstico por imagem , Animais , Ecolocação/fisiologia , Cabeça/anatomia & histologia , Imageamento por Ressonância Magnética/métodos
16.
Br Poult Sci ; 56(3): 293-8, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25906384

RESUMO

1. A study was conducted to evaluate the carcass composition of 1083 live birds using ultrasonic and morphological measurements and to estimate the genetic relationship between predicted and dissected carcass composition in Japanese quail. 2. Birds were reared for 35 d, and morphological measurements consisting of the length and width of breast muscle were recorded for all birds using a digital caliper. After slaughtering, the weight and percentage of carcass traits were measured on chilled carcasses. The dimensions of breast muscle were measured in 638 birds with an ultrasound scanner before slaughter at 35 d of age. 3. Genetic parameters from univariate and bivariate analyses were obtained by restricted maximum likelihood using ASREML software. 4. Genetic correlations between body weight at 35 d (BW35) and the percentage of carcass traits were low. Therefore, selection for BW35 may not effectively improve the yield of carcass components in Japanese quail. 5. High genetic correlations between carcass traits and ultrasonic measurements compared to morphological measurements suggest that the ultrasonic technique is a better method to improve breast weight and yield in Japanese quail.


Assuntos
Coturnix/fisiologia , Carne/análise , Animais , Coturnix/anatomia & histologia , Coturnix/genética , Dissecação/veterinária , Feminino , Masculino , Ultrassonografia/veterinária
17.
Hum Exp Toxicol ; 34(6): 668-76, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25233897

RESUMO

There are increasing concerns regarding the toxic effects of chlorpyrifos (CPF) on human health. Curcumin (CUR) is a yellow pigment isolated from turmeric ground rhizome of Curcuma longa Linn., which has been identified as an antioxidant agent. This study was designed to examine the protective effect of CUR and vitamin E (Vit E) on CPF-induced lung toxicity. Rats were divided into seven groups: control, CPF (13.5 mg/kg, orally), CPF + CUR (100 and 300 mg/kg, respectively, orally), CPF + α-tocopherol (Vit E, 150 mg/kg, intraperitoneally), CPF and CUR (100 and 300 mg/kg, respectively) in combination with α-tocopherol. The regimens were administered once daily for 28 days. At the end of the treatment period, lungs were collected for evaluation of oxidative factors and histopathological parameters. CUR and Vit E led to a decrease in lipid peroxidation in the lungs of the CPF-injected animals (48% and 51%, respectively). Glutathione peroxidase inhibited by CPF (91.9 nmol/min/mg protein) was induced again by CUR and Vit E (167.1 and 171.8 nmol/min/mg protein). CUR and Vit E caused a significant induction of superoxide dismutase (103.4 U/mg protein). Catalase activity almost returned to normalcy in CPF-intoxicated rats subjected to CUR + Vit E treatment (p < 0.001). Lung sections from CPF-treated rats displayed histopathological damages, while coadministration of CUR and Vit E resulted in apparently normal morphology with a significant decrease in injuries (p < 0.05). Our findings revealed that coadministration of Vit E and CUR to CPF-treated animals prevents the oxidative damages in the lung tissues.


Assuntos
Antioxidantes/farmacologia , Clorpirifos/toxicidade , Curcumina/farmacologia , Pulmão/efeitos dos fármacos , Vitamina E/farmacologia , Animais , Catalase/metabolismo , Glutationa Peroxidase/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Pulmão/metabolismo , Pulmão/patologia , Masculino , Estresse Oxidativo/efeitos dos fármacos , Ratos Sprague-Dawley , Superóxido Dismutase/metabolismo
18.
Hum Exp Toxicol ; 32(5): 544-53, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23696423

RESUMO

Type I diabetes mellitus is a metabolic disease caused by the impairment of pancreatic ß-cells mainly mediated through oxidative stress and related apoptosis. Islets transplantation seems a promising treatment for these patients, but during islets transplant, various types of stresses related to the isolation and transplantation procedure compromise the function and viability of islets. We recently hypothesized that the combination of cerium oxide (CeO2) and yttrium oxide (Y2O3) nanoparticles with a potential free radical scavenger behavior should be useful to make isolated islets survive until transplanted. In the present study, oxidative stress-induced apoptosis in isolated rat pancreatic islets exposed to hydrogen peroxide (H2O2) and the protective effects of CeO2 and Y2O3 nanoparticles were investigated. Exposure of islets to H2O2 (50 µm, 2 h) increased intracellular oxidant formation such as reactive oxygen species and subsequently apoptosis and decreased viability, glucose-induced adenosine triphosphate (ATP) production and glucose-stimulated insulin secretion. Pretreatment with CeO2 and/or Y2O3 nanoparticles reduced the oxidant formation and apoptosis and increased viability, glucose-induced ATP production and glucose-stimulated insulin secretion. These results suggest that this combination may protect ß-cell apoptosis by improving the oxidative stress-mediated apoptotic pathway.


Assuntos
Apoptose/efeitos dos fármacos , Cério/farmacologia , Ilhotas Pancreáticas/efeitos dos fármacos , Ítrio/farmacologia , Trifosfato de Adenosina/biossíntese , Animais , Caspase 3/metabolismo , Caspase 9/metabolismo , Insulina/metabolismo , Secreção de Insulina , Ilhotas Pancreáticas/patologia , Masculino , Nanopartículas Metálicas , Ratos , Ratos Wistar , Espécies Reativas de Oxigênio/metabolismo
19.
Bone Joint J ; 95-B(2): 192-8, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23365028

RESUMO

Van Nes rotationplasty may be used for patients with congenital proximal focal femoral deficiency (PFFD). The lower limb is rotated to use the ankle and foot as a functional knee joint within a prosthesis. A small series of cases was investigated to determine the long-term outcome. At a mean of 21.5 years (11 to 45) after their rotationplasty, a total of 12 prosthetic patients completed the Short-Form (SF)-36, Faces Pain Scale-Revised, Harris hip score, Oswestry back pain score and Prosthetic Evaluation Questionnaires, as did 12 age- and gender-matched normal control participants. A physical examination and gait analysis, computerised dynamic posturography (CDP), and timed 'Up & Go' testing was also completed. Wilcoxon Signed rank test was used to compare each PFFD patient with a matched control participant with false discovery rate of 5%. There were no differences between the groups in overall health and well-being on the SF-36. Significant differences were seen in gait parameters in the PFFD group. Using CDP, the PFFD group had reduced symmetry in stance, and reduced end point and maximum excursions. Patients who had undergone Van Nes rotationplasty had a high level of function and quality of life at long-term follow-up, but presented with significant differences in gait and posture compared with the control group.


Assuntos
Ectromelia/cirurgia , Fêmur/anormalidades , Desigualdade de Membros Inferiores/cirurgia , Procedimentos Ortopédicos/métodos , Adolescente , Adulto , Criança , Feminino , Fêmur/cirurgia , Seguimentos , Humanos , Desigualdade de Membros Inferiores/congênito , Masculino , Pessoa de Meia-Idade , Procedimentos Ortopédicos/efeitos adversos , Qualidade de Vida , Amplitude de Movimento Articular , Inquéritos e Questionários , Resultado do Tratamento , Adulto Jovem
20.
Case Rep Orthop ; 2012: 439836, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23259122

RESUMO

Penetrating wounds of the foot are not uncommon. Many are caused by thorns or by fragments of wood that are retained in the foot, creating a foreign-body granuloma. The differential diagnosis for bony reaction to an unrecognised organic foreign body includes osteoid osteoma, chronic and acute osteomyelitis, tuberculosis granuloma, bone cyst, aneurysmal bone cyst, cortical fibrous defect, and neoplasm. We report the case of a boy suffering from a thorn inducing a lytic lesion of the fifth metatarsal that demonstrates the diagnosis difficulties of foreign body granuloma.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...